The invention relates to a nonlinear electrical material with improved microvaristor filler (1′), to devices and electrical apparatuses comprising such nonlinear electrical material and to a production method thereof. According to invention, the filler (1′) comprises larger spherical particles (5) and smaller irregular particles (6) that are arranged interstitially and provide non-point-like and/or multiple contact areas (56, 56a, 56b, 66) owing to their irregular outer shape comprising edges and faces. Embodiments, among other things, relate to: spherical particles (5) being calcinated and broken-up to retain their original shape; irregular, spikly shaped, particles (6) obtained by calcinating or sintering and crushing or fracturing granules or blocks; and addition of a third filler fraction. Advantages, among others, are: higher filler contents, more and more durable inter-particle contacts (56, 56a, 56b, 66), enlarged effective micro-contact area, and improved electrical performance of the nonlinear electrical material.